Electron discharge tube



June 15, 1948. P. HAAS ELEcTRoN DISCHARGE TUBE Filed Dec. 9, 1945 INVENTOR AT1-ORNE Y from insulator plate 9 and reflector electrode 8. A short cylindrical wall 36 in the central part of cavity resonator 1 forms the inner part of the cavity resonator, to which are transversely joined accelerator grid I1 and first buncher grid I8. Second buncher grid I9 vis connected transversely across the central opening of flexible top plate I6 and to acentral opening in thebottom of shielding electrode I2. Electrode I2 is generally cupshaped, having a iiat annular disc-shaped bottom 318 and cylindrical wall 39. Four right-angled metal struts I3 are firmly attached at their lower ends to the top of electrode I2, passing through four holes 4I in insulator disc 9. At their upper ends, the struts I3 are welded or. otherwise rigidly connected to metal plate I4, which is carried at its center 42 by movable shaft 20 passing tlirouglfi tubing 2 I.

As described so far, it is evident that any motion of shaft 2!) with respect to tubing 2l in axial direction (i. e., up and down in the figure) will be transferred to an equal motion of grid I9, while the positions of grid I8 and reflector electrode 8 remain fixed. Top plate I6 of cavity resonator 1 is preferably made ofa metal disc having a series of circular corrugations. to facilitate an axial linear motion of grid I9. Oscillatory energy of `a frequency controllable by the distance between grids I8and I9 can be extracted from cavity resonator 1 by means of metalloop 2B and concentric transmission line 29, 3U passing through header 2. Concentric line 29, 30 may also be used as a bottom supportl for cavity resonator4 1, and may be supplemented by additional bottom supports rigidly attached to header2, if desired.

The motion of shaft 2i] inaxial direction is used for tuning the cavity resonator in accordance with the invention. In` order to separate the vacuum space in .the envelope from the external pressure entering .through top 43 of tubing 2l, a separating chamber 44 is provided at the lower end of tubing 2I and shaft 20. It consists of a rigid inverted conical metal wall 23, brazed in an air tight manner to .the lower end of shaft -20,jand of a flexible corrugated top disc 22, connected .atits inner periphery 21 in a vacuumtight manner .to tubing 2 I, and at its outer periphery 26 to the large diameter upper opening of conical wall 23. The flexible corrugated disc 22 is the only delicate and fragile part, of the tube which is exposed to air pressure, and it is easily seenV from the drawing that it is completely enclosed by the walls .of the glass envelope, and thus not exposed -to accidental external injury. The motion of shaft 20, and therefore. that of grid I9, is substantially entirely` a translational motion in axial direction, `and a tilting of gri-d I9, which mght lead to unsymmetrical distribution of the electron orbits with respect to the .tube axis, is prevented by the construction, as tubing 2I represents a long guide for shaft 20. The clearance between shaft 20 and tubing 2| can be made very small, without danger of sticking,

The translational motion of shaft 20 with respect to tubing 2I in the direction of the axis of these` .two parts may be controlled by nut 41, resting with a shoulder on top 43 of tubing 2 I, by means of cooperating threads 45 and 46 .cut into the nut 41 and into shaft 20. In this embodiment, the tension of the corrugated metal membranes 22 and I6. must be so yadjusted that it provides a downward pull on shaft 20. Turning of nut 41 tothe right Willthen lift the shaft mechanically. When` nut 41 is turned to the left, the elastic Pin liig. 2, wherein parts corresponding to those of Fig. l bear the same numerals primed.

In this embodiment of `the control member, the upper ends of shaft 2U and of tubing 2 I are provided with threads of different pitches, e. g. with thread 5I of 25 T. P. I. on shaft 20 and a. thread 49 of 20 T. P. I. on tub-ing 2i. Corresponding threads, 55 on the upper section of nut 52' and 48v on the lower section of nut 52 cooperate with threads 5I and 49 respectively. A full turn of nut 52' will thus produce a motion of shaft 20 with respect to tubing 2 I in axial direction equal to the difference of the full turn heights of the two threads, i. e., .050'l minus .040, viz., .010". Any other pair of pitches may, .of course, be 4chosen in place ofthe 25 and 20 T. P. I., which served forillustration inthe above example. The choice of the pitches depends on practical considerations.

Fig. 3 illustrates a further development of the differential screw control member shown in Fig. 2, wherein parts corresponding to those of Fig. 2 bear the same numerals. double primed. In Fig. 3, the threads 49 and 5I" are not cut directly into tubing 2l and shaft 20", but separate sleeves 53 and 54 are threaded, with threads 49 and 5I, whose pitches are chosen as described in connectionwith Fig. 2. These threaded sleeves are brazed to tubing 2 I and shaft 20" at a certain stage. of processing of Ithe tube, as will be explained later on. Nut 52 consists of two parts, lower section 55 and cap 51. Thread 48" is cut into the lower part of section 55. It has the same pitch as thread 49 ofthe sleeve 53. Nothread is out into .the upper pa-rt of nut 52", which would nt into thread 5I of sleeve 54. A separate pretuningnut 55 is provided, having a thread 50" equal in pitch to that of thread 5 I of sleeve 54". The outer diameter of pretunlng nut 56 is slightly less .than the inner diameter of the upper unthreaded part. of section 55. The lower end of pretuning nut 56 rests on a shoulder 58 of nut 52". Aften` nut 52 has been screwed in over tubing.' 2|, pretuning nut 56 is inserted into thread 5I,, `until Iits lower end res-ts on shoulder 58 of nut 52". The purpose of pretuning nut 56 is to adjust the center tuning range around which the tube isdesired to operate. Accordingly, nut 55 is turned until the. :correct center tuning range is .obtained. .When this adjustment has been made, it may be braaed withits outer surface to the inner surface of :lower section 55. Finally, cap 51 is joined to top 59 of 'section 55, preventing any dust entering into the control member.

The construction of the external control as described in connection with Fig. 3 has various advantages over that of Fig. 2, In the rst place, it permits the use of materials for tubingz I and shaft 2D" having uniform wall-thickness and uniform outer diameter. The pretuning nut 56 facilitates. a convenient control of the tuning range, .as a last operation after the tube is processed and exhausted. It is,v of course, desirable that the tuning threads48, vMI and and 5I are 4not exposed to the high temperatures .the moticncdffshafti-zn .annota eireenensfby the control'nut i512, WhileI the lsing-le screw 'tuning 'controler' Eig. `1 relies on elastic forces "inthe metal membranes rv22 yand '16 for the "downward motion-of shaft. i 'f @Whileadjustingmechanism'of the 'invention-is describdffin fdetailin its Ja'pplication for-tuning :aree'x "klystron, `lit f 'is of course understoodllthat thisfis 'lme'relyvdone or purposes 'f "illustranot by wiayof limitation. flForfia'detailed explanation of hthe operation- V`df theiireexdklystronreference `rnay"be'fhadtofU. LS. Paten-t No- 12,250,541, cthe-#disclosure vfnigvvliiehv is expressly -incor-p'orated'fherein' byf-re'fere'nce.

What is claimed is:

-1.-"An'electron tube comprising an evacuated enclosing glass envelope, a vtubular metal member sealed through oneend ofsaid envelope, a lshaft-'mounted for sliding movement insaid tubular member, expansible meanslocate'd Within said envelope .and `sealing the inner end of said tubular member to said Ashaft to allow'said shaft to slidewhile mamtainingthevacuum wthi-nthe Eerim'eloipeja cavity resonator *within thene'vacuated spaceffof ,said envelopexsooniprising `ail'med Aboundary flwsall ,and .a movable :lboundary 'lwalL .ineansirigidly -connecting said movable wail-ld; 'the inner fendof said shaft, .meansf rigidly connecting said xed .Wiall to said'-tubularfmembenmeans external v.of `the yenvelope and icoiinecte'd =toflsaid vshaft ior controlling the sliding l.fadjus'itrne'nt lof said shaft in said tubular member, and a cathode within the envelope for projecting an electron stream into said resonator.

2. An electron tube, comprising an enclosing envelope, an electrode system within the envelope comprising in longitudinal array an electron` emitter, a cavity resonator, a shield electrode and an electron reflector electrode, means supporting said resonator said reflector and shield as a unit from one end of the envelope comprising a tubular metal member sealed vacuum-tight through said end of the envelope, a flexible metal member sealed to the inner end of said tubular member and located wholly Within said envelope, a metal rod passing through said tubular member and connected vacuum-tight to said flexible member, means connecting said resonator to the inner end of said rod, means connecting said resonator to said tubular member, and means insulatingly supporting said reflector electrode from said tubular member.

3. An electron tube comprising an enclosing glass envelope, a tubular member sealed vacuumtight through said envelope, a plurality of support rods extending parallel to said tubular memberjffrrieansrigidly"fastenedtoisaid tiibiilarni'emf brfarid to fivhichi sai-dlsupportfrdds 1are fastened at '1one#--erd, a cavity l' resonator Hfast'endlto iene oppositeienfds'of said r-ods," one=--wall of-said resonatorbeing movablewvithfrespect-to i anther 4till, 'spacedllalignedfgrids carried "frespectivlyl'b lie movable-Wall afndthe,xediwallfa shiizl'able`l 4imiiirig 'l throug-hsaid t-u'bular 1 member and frigidlyl V-oox-i-neeted atffits inner' -endfto said movable Wall, f'exiblei dlaphragm-l-ike mea-ns lo'catd :entirely Within fthe-envelope and :providing da moviblefbiitwaenum-tight?ointl between''saidtubillar 'memberfarid isaidl-slidable.f-rod; fmeansfex- A:ternal-"tto isa-id* I en'velope:and connected?` to saidftrdd forfaldjllstngthelposition'df-said rod and thereby adjusting the yposition rof sani movablefwallarid an electron emit-'ter cathode vlWitlfiin :said envelope Lfor "projecting electrons 'into #said @cavity -resotraitor. y

-1"4."`=A-n *electron tube `r`accordi-ng '-to claim '-13 'iin which a reflector'electrodeffis insulatingly'supported r4f'from A-sa'id support rods in spaced^ relation tolsad resonator.

"5. An electron tube f according vto'ielaim 5'3 17in lfovhich a-concerti-triclineA is `vacuunr-"tight sealed throng-lrl the wall ofsaid envelope andi is-co'nnected to said "resonator forming IanL additional support" therefor, said *transmission*lmet-terminafting in-*a llooped 'portionf locatedlwithin-'fsaid resonator. d 1

f Anf e1ectrn=tube 'off thefiklystronf'ftypa com-- :prisingan enclosing evacuated envelope, aficavtity resonator-*Within ther kenvelope comp'rlsingan annular trough-like 3member Iof' -rigid 'LmetL-ir'st and *second grids -r attached y-tran'sversely across theiinner annularwall -oisa'id troughilike 'mem- 'ber'in '-spacedfrelation ltoi each-other, `fafifleiible lannular '-'tliap1f1'1agm,A ajthir'dgrid y.att'ached trans; v erselyi'ito the yinneriannularmargin#of said? ilexiblei annular diaphragm; `lmeans biasinglsaid Adia"- phra'gmfwith said: third? grid carriedE 2therebyfin spaced" relationfito fsaid -secon'd l' grid, af' redactor veletrdde insulating-ly mounted -in -alignmen-t with saidgrids and in spaced relation Ato said third grid,4a reciproeable 1rodfpas`sing= through fthe wall -of 'the' xenvelope and connected 'to-"said "diaphragm, "a tubular metal fmeinberllthr'ough ywhich''said rod'ip'asses Aand sealedrvacuum-Jtight through-the envelope Wall; the 2inner vend fof aid tbularmetalmember'fbeing-vacuumetight e'ald `to'tlie"finn`e`r end-of said' rod by'fmeansbfailexible corrugated metal member located entirely Within the envelope, means external to the envelope and connected to said rod for adjusting said rod and said third grid, an electron-emitting cathode for projecting electrons into said cavity resonator.

7. An electron tube according to claim 6 in which a shield electrode surrounds said reector electrode, sai-d shield having an opening in alignment with sai-d grids and rigidly supported from the end of said rod.

8. An electron tube of the reeX klystron type, comprising an enclosing evacuated envelope, an elongated tubular metal member sealed vacuumtight through said envelope, a pair of support rods rigidly supported at one end from said tub-ular member, a cylindrical metal member rigidly fastened to the lower ends of said rods, said cylindrical member having a iiat annular peripheral ange, an annular trough-like metal member also having a at annular peripheral flange in abutting relation with the first-mentioned ange, a corrugated iiexible metal annular member fastened at its outer margin between saidabutting flanges, first and second grids extending transversely across theV inner annular wall of said trough-like member in spaced relation to each other, a third grid extending transversely across the central opening in said corrugated annular member, a cup-like metal shield member having a central opening in its bottom and fastened to the inner margin of said corrugated annular member, a reflector electrode carried by an insulator member extending between said support rods, said reilector electrode being in alignment with said grids, an adjusting rod extending through 4said tubular metal member and connected at its lower end to said shieldmember, means external to said envelope and connected to said rod for adjusting said rod and thereby to vary the position 4of said third grid with lrespect to said second grid and with respect to said reector electrode, and an electron-emitting cathode for projecting electrons into the space between said first and second grids.

9. A tube according to claim 8 in which said trough-like member and said corrugated annular member formv a cavity resonator, and a concentric transmission line is vacuum-tight sealed through said envelope and terminates in a metal loop which extends into said cavity.

10. An electron tube, comprising an evacuated enclosing envelope, an electrode system mounted within said envelope including an adjustable electrode whose position is adjustable with respect to one or more of the other electrodes, mean-s to effect said adjustment externallyof the envelope while maintaining the vacuum, the lastmentioned means including va tubular metal member vacuum-tight sealed through the envelope, a rodpassing through said tubular metal member an-d connected to said adjustable electrode, said rod and tubular member each havinga portion external of the envelope, each external portion carryingr a separate threaded section of dif.- ferent pitch, a differential adjusting nut cooperating with said threaded sections, and `an electron emitter for projecting electrons into the space between said electrodes.

11. An electron tube accordingv to claim 10 in which the external en-d of said tubular metal member carries an external threaded sleeve and the external end of said rod also carries a threaded sleeve, and means are provided to set the n-ormal position of said rod with respect to said .tubular member comprising a threaded nutcooperatingwith the thread'on the first-,mentioned sleeve, and another threaded nut cooperating with the thread on the second-mentioned sleeve, said nuts -being independently adjustable to Aset said normal position, means fastening the nuts together as a unit, and. differentially threaded means engaging said nuts to effect a diierential movement of said rod for adjustment of the position of said adjustable electrode,

12. An electron tube construction of the klystron type having an enclosing envelope, a movable electrode within the evacuated envelope of the tube, and meansto effect adjustment of said electrode While maintaining the vacuum, the lastmentioned means including a tube sealed through said envelope, a slidable rod passing through said tube and the envelope and connected to the movable electrode, and a flexible corrugated metal plate vacuum-tight sealed between the inner end of the rod and the envelope, said plate being wholly located within the envelope whereby it is protected by the envelope against injury.

13. An electron discharge device having an evacuated envelope, a tubulation sealed into and through the wall of said envelope, a rigid rod telescoped through said tubulation and extending at one end into the envelope, the Iother end of the rod being accessible externally of the envelope, an electrode Within the envelope and movably mounted therein, a connection between said rod and said movably mounted electrode, and expansible vacuum-tight means sealing the` inner end of said tubulation.

PAUL HAAS.

REFERENCES CITED The yfollowing references are of record in the file of this patent: Y 

